Parts of a gas turbine engine can become scratched or cracked by normal wear, stress loading, or by incident such as foreign object impact at high velocity. Some of the parts of the gas turbine engine are made of a substrate and of at least one coating over the substrate. Cracks in the coating can expose the substrate, which in turn can leave the component vulnerable to stress fractures, such as stress corrosion cracks whereby in the presence of stress and corrosion the component would crack and fracture at a stress level below the tensile strength of the substrate.